The announcers: Joe Buck and Troy Aikman in the booth and Pam Oliver and Erin Andrews reporting from the sidelines.

The coaches: Green Bay's Mike McCarthy is 88-49-1 (including 6-4 in the postseason) in his eighth season as the Packers' coach and as an NFL head coach. San Francisco’s Jim Harbaugh is 39-13-1 (including 3-2 in the postseason) in his third season as coach of the 49ers and as an NFL head coach.

The series: The Packers lead the all-time regular-season series, 30-27-1, and the postseason series, 4-2. The 49ers have won the last three meetings, including a 45-31 victory over the Packers at Candlestick Park in the 2012 NFC Divisional Playoffs.

The rankings: The Packers’ third-ranked offense was No. 7 in rushing and No. 6 in passing in the regular season. Their 25th-ranked defense was No. 25 against the run and No. 24 against the pass. The 49ers’ 24th-ranked offense was No. 3 in rushing and No. 30 in passing. Their fifth-ranked defense was No. 4 against the run and No. 7 against the pass.

New man: The Eddie Lacy the 49ers saw in Week 1 and the Eddie Lacy they saw on film as they prepped for Sunday’s game couldn’t be more different. The Lacy that made his NFL debut was indecisive, lost a fumble and was – yes, nervous.

“Oh yeah, in that game? Yeah. He definitely had some big eyes,” running backs coach Alex Van Pelt said at midweek. “He warmed up as the game went on. I think he figured out this is just football, but the start of that game there were definitely some jitters.”

That may be surprising given that Lacy played the collegiate version of pro football at Alabama, where appearances in the BCS Championship Game are an annual occurrence. Whatever jitters he felt that day, though, he has overcome since. Lacy finished the regular season having rushed for 1,178 yards (4.1-yard average) and 11 touchdowns in essentially 14 games, as he suffered a concussion on his first carry in a Week 2 victory over Washington and missed the following week’s game against Cincinnati.

“It’s not uncommon for a rookie get that feeling going into the first game. Haven’t seen it since,” Van Pelt said. “Once he started rolling in that game, I think he felt, ‘This is what I do.’”

The Packers will need him to do what he does in order to win Sunday. Lacy has been bothered by a sprained right ankle since initially injuring it Dec. 8 against Atlanta, and it was bad enough that he wore an orthopedic immobilizing walking boot throughout the weeks that followed. But this week, Lacy practiced on Thursday in pads for the first time since the injury. Against the No. 4 run defense in the league, it will be tough sledding, but Lacy understands how vital he will be.

“I definitely feel a lot better,” Lacy said. “I think I developed a lot (since the opener). I'm playing a lot faster, a lot calmer. I think I'm a much better player now than I was then.

“I can't even start to describe how I felt that game. That was the first time for me, but it's in the past, so I'm not too much worried about it.”

Run, run, run: Packers fans may find it hard to believe after watching Colin Kaepernick throw for a career-high 412 yards in the regular-season opener against their team – and not have another 300-yard passing game until last week’s regular-season finale – but the 49ers’ offense is predicated on running the football. And we’re not talking the read-option here. Running back Frank Gore finished ninth in the NFL in rushing – right behind Lacy – with 1,128 yards, and with 505 rushing attempts, only the Buffalo Bills (546) and Seattle Seahawks (509) ran the ball more often during the regular season.

Defensive line coach Mike Trgovac said his gut feeling was that the only team the Packers faced this year that was more run-oriented was Minnesota, and while the stats might not bear that out, there’s another factor: The 49ers are variable in their run game, using different schemes and personnel groups. The 49ers frequently bring in an extra offensive lineman to run block, a la Mike Sherman’s old U-71 package with Kevin Barry back in the early 2000s.

“Minnesota probably doesn’t have as much variation as they have. Minnesota just runs that I-back and lets [Adrian Peterson] take over,” Trgovac said. “They have a lot of different variations and they’ve got a guy holding the ball that can run.

“Against this team, you have to let your instincts take over because they give you a lot of different stuff. They’re a power team. They’re an option team. They run misdirections. They’ll run the fullback plays and they’ll run the counter plays, so you just have to let your instincts take over because they do a lot of stuff running the ball.”

Let’s not forget that Kaepernick is certainly capable of running like crazy, as evidenced by his 181-yard effort in the Packers’ NFC Divisional Playoff loss last year. This year, Kaepernick finished the regular season having run 92 times on designed runs and scrambles for 524 yards (5.7-yard average), including seven attempts for only 22 yards in the season opener.

“It’s tough. It’s tough. We take away him running and he’ll beat you throwing,” veteran defensive tackle Ryan Pickett said. “Dual-threat quarterbacks are always a defense’s nightmare. It’s going to be tough but we feel confident in our game plan and what we have in store.”